Printed png with black background
Description
Printing an eeschema shhet after pnb insertion the printed png background is black.
Original sheet

Steps to reproduce
Open a new sheet in eeschema -> Place -> Add Image
select a png or BMP image with no color background
print the sheet with microsoft PDF printer or via some other printer to obtain the "black background"
KiCad Version
Application: KiCad (64-bit)
Version: (6.0.2-155-g23479821e3), release build
Libraries:
wxWidgets 3.1.5
libcurl/7.78.0-DEV Schannel zlib/1.2.11
Platform: Windows 10 (build 19043), 64-bit edition, 64 bit, Little endian, wxMSW
Build Info:
Date: Mar 2 2022 22:09:59
wxWidgets: 3.1.5 (wchar_t,wx containers)
Boost: 1.76.0
OCC: 7.6.0
Curl: 7.78.0-DEV
ngspice: 36
Compiler: Visual C++ 1928 without C++ ABI
Build settings:
KICAD_USE_OCC=ON
KICAD_SPICE=ON
Application: Editor schemi KiCad (64-bit)
Version: (6.0.2-155-g23479821), release build
Libraries: wxWidgets 3.1.5 libcurl/7.78.0-DEV Schannel zlib/1.2.11
Platform: Windows 10 (build 19043), 64-bit edition, 64 bit, Little endian, wxMSW
Build Info: Date: Mar 2 2022 22:09:59 wxWidgets: 3.1.5 (wchar_t,wx containers) Boost: 1.76.0 OCC: 7.6.0 Curl: 7.78.0-DEV ngspice: 36 Compiler: Visual C++ 1928 without C++ ABI
Build settings: KICAD_USE_OCC=ON KICAD_SPICE=ON
